<Related Art>
Conventionally, a new fine processing technology has been developed in accordance with high integration and high performance of LSI. A chemical mechanical polishing (hereinafter, also simply referred to as CMP) method is one of those technologies, and CMP is often used in an LSI manufacturing process, particularly in processes such as shallow trench isolation (STI), planarization of interlayer dielectric films (ILD films), formation of tungsten plugs, and formation of multilayer interconnections composed of copper and a low dielectric film. Among them, in STI, a layer that contains a substance having a pH range exhibiting a positive zeta potential in an aqueous solution of pH 6 or lower (for example, a layer of silicon nitride) is used as a stopper and a layer of silicon oxide is generally polished and removed by CMP, for example.
As disclosed in Patent Literatures 1 to 3, use of cerium oxide abrasive grains for specific CMP applications such as STI is known.